FAQ: "I am working with a customer who would like to measure corrosive liquids in the HunterLab sample cup
They would like to make a Teflon or Delrin reflector as this is not affected by the corrosive liquid.
1) The disk assembly comes with a black ring for height – does this have to be black to absorb color or can they use a white Teflon ring?
2) Any suggestions for the design of the reflector?
The CFEZ or CLFX views a 25 mm diameter area. This viewed area is much less than the 65 mm diameter bottom of a sample cup. So, the color of the ring really will have no effect on the measurement. We use black rubber rings or black Delrin because black minimizes reflections and is a good safe choice. However, given the viewed area is much smaller than the edges of the sample cup, white Teflon could be used without a problem.
It would be advised that the reflector be modeled after our disk design with flat round with a handle so that the disk can be lowered easily onto the ring. I would suggest the Teflon disk be made thick enough to be effectively opaque, and your client might want to machine disk + handle out of one piece for structural stability.
A further thought for consideration is that if this corrosive liquid is dark and colored, a 5 mm high ring would be best to maximize transflected signal. If the sample is less colorful, near water, a 12 mm high ring similar to our standard ring height would be recommended.